1. Field of the Invention
The present invention relates to a novel black photosensitive resin composition and a light-blocking layer using the same. More specifically, the present invention relates to a black photosensitive resin composition which is suitable for being applied to a touch panel and a light-blocking layer using the same.
2. Description of Related Art
In recent years, liquid crystal display (LCD) has been wildly applied to various kinds of electronic devices such as mobile phone, personal digital assistant (PDA), digital camera, computer screen or notebook computer screen. In particular, based on the consideration of easily carrying and using, a touch panel, which can be directly touched by users for operation, has become a major development aspect of many electronic products.
Generally, in order to improve a contrast or color purity of a display, a light-blocking film would be disposed in the LCD for preventing a light leakage phenomenon between pixels and maintaining high image quality. Usually, an inorganic film containing chrome black (chrome and/or chromium oxide) is used to prepare the light-blocking layer. However, not only is the high production cost of the light-blocking layer/film containing chrome black high, but it also has problems of environmental pollution. Thus, in related arts, the light-blocking layer/film has been prepared by using a resin composition including inorganic particles such as graphite, iron oxide black, titanium black, and carbon black. Among them, graphite may lead to a decrease in the contrast of a display due to an increase in reflectivity, and titanium black, although having a more preferred impedance, has the disadvantages of poor dispersion and high price. Therefore, the use of carbon black seems to be a better choice. However, when carbon black is used as black pigment, the increase of the optical density may cause the problem with decrease in the impedance of the black matrix, so that a short circuit would happen during the back-end layout process in a touch panel. On the other hand, because the impedance of the black matrix would be decreased under a high temperature environment, ITO short-circuit is caused by a high temperature of the back end process of the panel (reaching to 280° C). Therefore, in order to meet the requirement of the industry, there is a need for developing a black photosensitive resin composition that can satisfy the requirements of optical density and high temperature electrical resistance, and presents excellent adhesion, good moisture resistance and etching resistance.